Polished fossil Oncolite slab. ONC112 green OG201 Polished orbicular granite slab

OG201   Polished orbicular granite slab

U112 Unakite rough rock

Weight  is 349 grams

Weight is 504 grams

OJ187  A slab

Polished fossil Oncolite slab. ONC112 green OG201 Polished orbicular granite slabONC112. Fossil Oncolite polished slab. From the Miocene "Trealla Limestone" north of Carnarvon, Western Australia . Age is approx. 15 million years. Dimensions at widest points approx. 145 mm x 105 mm x 8 mm thick. Weighs 285 grams. Oncolite is a limestone composed largely of oncoidsrounded, coated grains that grow as thin layers of lime mud accumulate around a tiny nucleus (such as a sand grain or shell fragment) under microbial influence. Formed in